1. Field of the Invention
Embodiments of the present invention generally relate to wellbore completion, and more particularly, to tubular connections.
2. Description of the Related Art
In order to access hydrocarbons in subsurface formations, it is typically necessary to drill a borehole into the earth. The process of drilling a borehole and of subsequently completing the borehole in order to form a wellbore requires the use of various tubular strings. These tubulars are run downhole where the mechanical and seal integrity of the jointed connections are critically important.
Generally, male to female threaded connections connect multiple tubular members end-to-end. The male end is referred to as a pin and the female end as a box. The tubulars are connected, or “made-up,” by transmitting torque against one of the tubulars while the other tubular is typically held stationary. Transmitting torque in a single direction corresponding with connection make-up tightens the threaded joint in order to establish the seal integrity and lock in the applied torque.
When running tubulars, there is sometimes a requirement to run jointed tubulars that will later be expanded by various types of expansion mechanisms. The basic type of expander tool employs a cone-shaped body, which is run into a wellbore at the bottom of the casing that is to be expanded. The expander tool is then forced upward in the wellbore by both pulling on the working string from the surface and applying pressure below the cone. Pulling the expanded conical tool has the effect of expanding a portion of a tubular into sealed engagement with a surrounding formation wall, thereby sealing off the annular region therebetween. More recently, rotary expander tools have been developed. Rotary expander tools employ one or more rows of compliant rollers that are urged radially outwardly from a body of the expander tool in order to engage and to expand the surrounding tubular. The expander tool is rotated downhole so that the actuated rollers can act against the inner surface of the tubular to be expanded in order to expand the tubular body circumferentially. Radial expander tools are described in U.S. Pat. No. 6,457,532, issued to Simpson et al., which is incorporated herein by reference in its entirety.
One problem that may occur during a completion operation is that the tubular string may get scratched when the tubular string contacts a portion of the wellbore when the tubular string is lowered into the wellbore. Normally, a scratch on a tubular does not affect the integrity of the tubular. However, a scratch on a tubular connection between the tubulars may be problematic. For instance, if the scratch occurs on the box portion of the tubular connection near the thin face of the box, then the box portion may split apart when the tubular connection is expanded. As such, the structural integrity of the entire tubular connection may be compromised.
Therefore, a need exists for an apparatus and a method to protect expandable tubular connections, thereby maintaining the mechanical and/or sealing integrity of the connection.